Input Quantization Noise Analysis 1.1 2003/07/16 16:31:40 GMT-5 2004/12/29 16:41:59.868 US/Central Douglas L. Jones dl-jones@uiuc.edu Douglas L. Jones dl-jones@uiuc.edu Kyle Clarkson kclarks@rice.edu quantization noise Signal-to-noise ratio SNR Analog-to-digital converters introduce quantization noise due to their finite wordlength. The signal-to-noise ratio (SNR) increases by 6 dB per bit. All practical analog-to-digital converters (A/D) must quantize the input data. This can be modeled as an ideal sampler followed by a B-bit quantizer.

The signal-to-noise ratio (SNR) of an A/D is SNR 10 10 P x P n 10 10 P x 10 10 Δ B 2 12 10 10 P x 4.77 6.02 B where P x is the power in the signal and P n is the power of the quantization noise, which equals its variance if it has a zero mean. The SNR increases by 6dB with each additional bit.